1. Field of the Invention
The present invention generally relates to injection molding machines and, more particularly, to an injection molding machine having a display apparatus.
2. Description of the Related Art
Generally, in an injection molding machine, various sensors including a pressure sensor are provided in each part so as to acquire detection signals as molding data from the sensor. The acquired molding data is used for determination of molding conditions and check of a molding operation. In order to make use of the molding data easier, the molding data is displayed as a waveform chart (graph) on a screen of a display unit.
Japanese Laid-Open Patent Application No. 5-42575 discloses a display apparatus of an injection molding machine, which comprises a group of sensors, an input unit, a microcomputer and a display unit. The display unit of the injection molding machine disclosed in this patent document selects one of a plasticization/measuring process, an injection process and a die opening/closing process, and displays the molding data of the selected process on the display unit.
Since a profile display of molding-data profile enables an instantaneous quality judgment of a state of injection molding, the display of molding-data profile is very convenient when running continuously an injection molding machine. Hereinafter, the profile display may be referred to as a waveform display. A plurality of processes of an injection molding are not independent from each other, and the processes are related mutually. Accordingly, it is more convenient if molding data regarding a plurality of processes (for example, two consecutive processes) can be simultaneously displayed on a screen of a display unit since the causal relationship between the processes can be grasped easily.
However, in a display apparatus of a conventional injection molding machine, only molding data of a predetermined drawing start timing can be displayed on a screen of the display apparatus. Therefore, in the display apparatus of the conventional injection molding machine, there is a problem in that molding data regarding two or more mutually related processes cannot be displayed simultaneously on the screen.